COLUMBIA — Give a mouse a cookie, and it'll ask for a glass of milk. But give a rat some junk food, and it might just say, "No thanks."
MU researchers used rats in a binge-eating study and found that deactivating a rat's brain region involved with emotion could block the consumption of certain foods but might not necessarily stop the craving.
Matthew Will, an assistant professor of psychological sciences at MU, said his team of researchers might have "short-circuited" brain networks associated with moving from craving to consumption.
"The hope is that the more detailed we can biologically define the feeding process from beginning to end, the more we will understand how to address a feeding disorder such as overeating," Will said.
The brain contains chemicals called opioids, which are released to reward pleasurable behavior. Opioids can produce binge eating in nonhungry rats and humans. In the study, rats were presented with a 40-percent-fat chunk of sugar, carbohydrates and protein that Will likened to cookie dough. The researchers deactivated the basolateral amygdala, a brain region associated with emotion, to block binge eating on fatty diets such as this.
"Since overeating is not a product of a hunger epidemic in this country but rather an addiction to food, this model is trying to figure out what in the brain regulates this latter type of feeding," Will said.
It is estimated that about 4 percent of the population has binge-eating disorder, which can cause medical complications such as obesity and heat disease.
Researchers also found that rats that had been deprived of food for 24 hours ate the same amount, regardless of whether the basolateral amygdala was out of action. Will said this confirmed the opioid feeding model represents binging driven by the pleasure aspects of food, instead of hunger.
Laurie Mintz, an MU psychology professor who has studied the prevention of eating disorders, said targeting areas of the brain might not be the best method.
"I don't think we should be going into people's brains and turning off their emotions, because they're a hugely important part of us as people," Mintz said. "I think we need to do interventions to help people deal with their emotions, not block them."
Will said this research could lead to more of its kind.
"It seems that we have a model that will help us isolate the circuits in the brain that control cravings," he said. "This would prove very useful in producing medical treatments to curb the overeating that contributes to obesity."